Honing machine and method for carrying out honing operations on orthogonally aliged bores in a workpiece

ABSTRACT

The invention relates to a honing machine and to a method for carrying out honing operations on orthogonally aligned bores in a workpiece, in particular for honing cylinder bores and a bearing race bore in a cylinder crankcase.

BACKGROUND

The invention concerns a honing machine and method for carrying outhoning operations on orthogonally aligned bores in a workpiece, inparticular for honing of cylinder bores and a bearing race bore in acylinder crankcase, with the characteristics of the preamble of claim 1,a honing machine with the characteristics of the preamble of claim 2, ahoning machine with the characteristics of the preamble of claim 4, anda method for carrying out honing operations on orthogonally alignedbores in a workpiece, in particular for honing of cylinder bores and abearing race bore in a cylinder crankcase, with the characteristics ofthe preamble of claim 8, a method with the characteristics of thepreamble of claim 9, a method with the characteristics of the preambleof claim 10, and a method with the characteristics of the preamble ofclaim 11.

The cylinder crankcase, often referred to as a “crankcase” or “engineblock”, is an integral component of combustion engines orinternal-combustion engines, as they, for example, are used in personalor freight vehicles, aircraft, ships, and stationary facilities. Themost common variant is the multi-cylinder engine, the pistons of whichare connected to the rotating crank shaft via con rods, and which conveythe force generated by the engine to the wheels, ship propellers,aircraft propellers, generators, or similar.

The cylinder crankcase is one example of a workpiece with orthogonallyaligned bores.

Within the engine block are multiple cylinder bores in a straightalignment. The crank shaft in straight or V-engines is below, in a boxerengine it is between the cylinders and rests against the cylindercrankcase in the bearings of the crank shaft bearing bore. The bearingsare usually slider bearings, sometimes roller bearings. In order toensure high concentricity of the crank shaft and thus minimize unwantedsigns of wear and vibrations during operation, the crank shaft must meetstrict form tolerance requirements. The bearings must also be highlytolerated with regard to their size and position in the cylindercrankcase.

The relatively strict tolerances of the pertinent parts of a combustionengine and a cylinder crankcase stem from the complex functions of theseparts. The shape, dimensions and surface topography of the cylinder borelargely determine the wear, friction, oil use, and emission values ofthe combustion engine as well as the performance and effectiveness basedon the friction. The compressed combustion chamber volume mainly affectsthe compression of the engine. This in turn affects the performance and,due to the course of combustion, the emission values and engine sounds.

The exact position of the crank shaft relative to the pistons orcylinder bores is, among other things, important for reducing wear inhighly strained engine parts. In particular, these are pistons/pistonbolts, con rods, and con rod bearings on the crank shaft, as well as thebearing of the crank shaft in the cylinder crankcase. For the positionof the bore axis not only the absolute position in the space, but alsothe angle position or orientation plays a role. For example, in controlgears with a coupling, the crank shaft and entry shaft of the gear movetogether. This means that precise coaxiality of the two shafts iscrucial for a long service life.

SUMMARY OF THE INVENTION

The task of this invention lies in the provision of a honing machine anda method for carrying out honing operations on orthogonally alignedbores in a workpiece, as with the cylinder crankcase described above,wherein the bores in a workpiece can be processed with high precision,in a short time, with a secure method, completely by means of honing.

This task is achieved with a honing machine for carrying out honingoperations on orthogonally aligned bores in a workpiece, wherein thehoning machine comprises:

A machine base and a machine-internal transport system arranged on themachine base.

The transport system comprises a rotary table that rotates around avertical rotary table axis. The rotary table comprises multipleworkpiece intakes. The workpiece intakes are arranged offset from oneanother in the circumferential direction at a radial distance from therotary table axis such that a workpiece inserted into a workpiece intakecan be successively moved along a circular path and through variousworkstations of the honing machine via rotation of the rotary table. Inother words, the rotary table moves workpieces along a circular pathfrom one workstation to another. The transport system facilitates thequick passage of the workpieces between the various workstations. Therotary table can be designed as an elevating rotary table. The rotarytable or slab thereof can be round or have a different geometric shape,e.g., triangular or rectangular.

The machine-internal transport system, and in particular the rotarytable, make it possible, for example, to load and unload the workpieceintake with one single loading station. Unlike transport machines, it ispossible for the workpieces to exit the honing machine at the samelocation where they entered. This simplifies the loading and unloading,and in particular the coupling of the honing machine to an externalconveyor system. An external conveyor system can be used, if necessary,with other honing machines and/or with other processing machines tocreate a production line.

To this end, at least one of the workstations is a vertical honingstation comprising at least one vertical honing unit. The verticalhoning unit comprises having a honing spindle with a honing tool,wherein the spindle axis is aligned parallel to the rotary table axis.The honing of a vertically aligned bore is performed via a relativemotion rotating around a spindle axis and translatory along the spindleaxis, between the workpiece and the honing spindle or honing tool. Thisrelative motion is usually oscillating. The spindle is typically rotatedin the bore and moved back and forth along the bore axis.

Another workstation is a horizontal honing station comprising at leastone horizontal honing unit. The horizontal honing unit comprises ahoning spindle with a honing tool. The honing of a horizontally alignedbore is performed via a relative motion rotating around a horizontalspindle axis and translatory along the horizontal spindle axis, betweenthe workpiece and honing spindle or honing tool. This relative motion isusually oscillating. The spindle is typically rotated in the bore andmoved back and forth along the bore axis. However, when honing thehorizontally aligned bore, it may be configured that the honing tool isrotated and only translatory moved into and out of the bore one time.Typically, honing retainers of the tool are set to an oversize, meaningthat they have a processing diameter that is slightly greater than thediameter of the bore being processed.

The honing machine further comprises an actuator unit. This is designedand arranged such that the actuator unit moves the workpiece in order tocarry out the honing in the horizontal honing station.

The honing spindle of the horizontal honing unit can be arrangedimmovably in the honing machine, in particular during the honing. But itis also possible, that during the honing, in addition to the movement ofthe workpiece, the honing spindle of the horizontal honing unit alsomoves, in particular in inverted direction, to participate in theaforementioned relative motion between the workpiece and honing spindle.

The motion of the workpiece via the actuator unit can reduce the motionof the horizontal honing unit or, if the horizontal honing unit isimmobile, only be limited to the rotation of the honing spindle. Thisincreases the precision with which the honing spindle or honing tool canbe used during the honing. This results in a more precise overall resultof the honing operation.

Furthermore, the task at hand is also achieved with a honing machinewith the characteristics of the preamble of claim 1, in particular withthe characteristics of claim 1, wherein the machine-internal transportsystem is designed such that the workpiece is moved from the rotarytable to carry out the honing in the horizontal honing station. Thehoning is carried out outside of the rotary table. The workpiece istransported in particular outside of the circular path where the rotarytable moves the workpieces. It is possible for the workpiece to berotated and aligned outside of the rotary table. A device for moving theworkpiece from the rotary table, and that also returns the workpiece tothe rotary table, is typically provided. During the movement of therotary table, the workpiece does not leave the honing machine. Theprocessing is typically carried out outside of the rotary table, but onthe same machine base where the rotary table is also located.

Because the honing takes place outside of the rotary table, there is notransfer of unwanted vibrations and oscillations to the rotary tablecaused by the honing, or they are minimized. Other workpieces on therotary table are thus also unaffected by these vibrations oroscillations. This increases the precision during the processing of theworkpieces at the other workstations.

Furthermore, the task at hand is achieved with a honing machine with thecharacteristics of the preamble of claim 1, in particular with thecharacteristics of claim 1 or 2, wherein the horizontal spindle axisextends along a processing direction. The translatory relative motionduring the honing occurs along an axis specified by the processingdirection. The processing direction is parallel to a direction extendingradially through the rotary table axis, yet is spaced from the rotarytable axis. In other words, the processing direction runs along astraight line that does not pass through the center of the rotary table.

This means the horizontal honing unit can be more flexibly positionedand aligned on the honing machine. For example, multiple, in particulartwo horizontal honing units can be placed next to each other and/orparallel to each other on the honing machine. This results inacceleration of the entire process.

Furthermore, the task at hand is achieved with a honing machine with thecharacteristics of the preamble of claim 1, in particular with thecharacteristics of claim 1, 2, or 3, wherein the horizontal honingstation comprises a workpiece intake comprising a rotational device witha rotating axis parallel to the rotary table axis, with which thealignment of the workpiece can be changed. The honing in the horizontalhoning station can be carried out with a different alignment than in thevertical honing station.

This means the horizontal honing unit can be more flexible positionedand aligned on the honing machine. With an immobile workpiece or aworkpiece firmly positioned on the rotary table with a fixed alignment,the position and alignment of the horizontal honing unit would bespecified by the orientation or alignment of the workpiece.

With an advantageous configuration of the honing machine, allworkstations of the respective honing machine are arranged on a sharedmachine base. The alignment of the rotary table and at least one of allthe workstations on the machine base improves the compactness and speedof the honing machine.

In another advantageous variant of the honing machine, the honingmachine comprises at least two vertical honing stations. At least onevertical honing station comprises one vertical honing unit moveablyarranged on a portal-like carrier via sliders. All vertical honing unitscan also be moveably arranged on the portal-like carrier via sliders.The use of multiple vertical honing stations and/or vertical honingunits facilitates the simultaneous processing of multiple verticallyaligned bores. It is also possible for a vertical honing station tocomprise multiple vertical honing units, so that honing operations canbe simultaneously performed in multiple vertically aligned bores in aworkpiece in a vertical honing station. Accordingly, honing operationscan be simultaneously performed in multiple vertically aligned bores invarious workpieces in various vertical honing stations. The simultaneouscarrying out of multiple honing operations reduces the overallprocessing time of the honing machine.

At least one of the workstations can be an empty station or aworkstation for carrying out other processing operations, e.g.,chamfering.

In another advantageous variant of the honing machine, the honingmachine comprises four workstations. The first workstation is a loadingand unloading station, where a workpiece to be honed is placed on therotary table or removed from the rotary table.

A second workstation is designed as a first vertical honing station. Inparticular, it can be used for pre-honing.

A third workstation is designed as a horizontal honing station. Thehorizontal honing operations are carried out here.

A fourth workstation is designed as the second vertical honing station.It can be used for final honing.

The transport direction of the rotary table is from the first to thesecond, or rather the third to the fourth, workstation. After completingthe fourth workstation, the workpiece returns to the first workstation.The number of workstations and their respective design, namely as aloading/unloading station, two vertical honing stations, one horizontalhoning station, optimizes the total processing time of the workpiecesthrough as many simultaneous operations as possible, and alsofacilitates a honing machine as compact as possible, which worksprecisely. In particular, such a division can advantageously integratethe moving or tilting of the workpiece in the horizontal honing stationinto the work cycle. This applies accordingly to the acceleration of theworkpiece when it is being moved.

Furthermore, the task at hand is achieved by the invention's method forcarrying out honing operations on orthogonally aligned bores in aworkpiece with the characteristics of claim 8. The workpiece is movedduring the honing in the horizontal honing station. In particular, thehoning spindle of the horizontal honing unit is at least kept immobilein the direction of the translatory relative motion.

The movement of the workpiece can reduce the movement of the horizontalhoning unit, or, if the horizontal honing unit is immobile, limited tothe rotation of the honing spindle or a honing tool arranged at thehoning spindle. This increases the precision with which the honingspindle or honing tool can be used during the honing processing. Thisresults in a more precise overall result of the honing operation. Themethod steps described herein partially correspond to the structuraldesigns of the honing machines described. The benefits listed herein arealso present in the method steps.

Furthermore, the task at hand is achieved with a method with thecharacteristics of the preamble of claim 8, in particular with thecharacteristics of claim 8, wherein, in order to carry out thehorizontal honing, the workpiece is moved away from the rotary table,and the honing is carried out outside of the rotary table, in particularwherein the workpiece is moved outside of the circular path where therotary table moves the workpieces.

Because the honing is carried out outside of the rotary table, there isno transfer of unwanted vibrations and oscillations to the rotary tablecaused by the honing, or these are minimized. Other workpieces locatedon the rotary table are thus unaffected by these vibrations oroscillations. This improves the precision of the processing of theworkpieces at the other workstations.

Furthermore, the task at hand is achieved with a method with thecharacteristics of the preamble of claim 8, in particular with thecharacteristics of claim 8 or 9, wherein the horizontal spindle axisruns along a processing direction. The translatory relative motionduring the honing occurs along this axis. The processing direction isparallel to a direction extending radially through the rotary tableaxis, yet is spaced from the rotary table axis. In other words, theprocessing direction runs along a straight line that does not passthrough the rotary table axis.

This means the horizontal honing unit can be more flexibly arranged andaligned. For example, two horizontal honing units can be positioned nextto and parallel to one another. It is also possible to position ahorizontal honing unit and a measuring station next to and parallel toone another. This accelerates the overall process.

The task at hand is also achieved with a method with the characteristicsof the preamble of claim 8, in particular with the characteristics ofclaim 8, 9, or 10, wherein before the horizontal honing is carried out,the alignment of the workpiece is altered. It is also possible for thealignment of the workpiece to be altered during and/or after thehorizontal honing.

This means the horizontal honing unit can be more flexible arranged andaligned. In the event of an immobile or firmly positioned workpiece, theposition and alignment of the horizontal honing unit would be specifiedby the orientation or alignment of the workpiece.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics, details and advantages of the invention areapparent from the wording of the claims as well as from the followingdescription of example embodiments based on the illustrations. Theseshow:

FIG. 1 a top view of a honing machine described by the invention;

FIG. 2 a side view of the honing machine described by the invention asshown in FIG. 1;

FIG. 3 a top view of another example embodiment of a honing machinedescribed by the invention, and

FIG. 4 a side view of the honing machine described by the invention asshown in FIG. 3.

DETAILED DESCRIPTION

In the following description, as well as in the figures, correspondingcomponents and elements have the same reference sign. For the sake ofclarity, not all references signs are listed in all figures.

FIG. 1 shows a top view of a honing machine 10 described by theinvention for carrying out honing operations on orthogonally alignedbores in a workpiece 12. The honing machine 10 comprises a machine base14 where a transport system 16 is located. The transport system 16comprises a rotary table 18 that rotates around a vertical rotary tableaxis 20. Four workpiece intakes 22 are arranged on the rotary table 18,wherein each of the workpiece intakes 22 can receive one workpiece 12.Rotation of the rotary table 18 around the rotary table axis 20transports the workpieces 12 on a circular path. The workpieces 12 arethen led to the individual workstations. Four workstations are indicatedby four workpieces 12. The workstation shown on the right in FIG. 1 is ahorizontal honing station 24. The horizontal honing station 24 comprisesa horizontal honing unit 26 comprising a honing spindle 28 with a honingtool. The honing spindle 28 or honing tool is aligned along a horizontalspindle axis 30. The horizontal honing operation is thus carried outalong this horizontal spindle axis 30.

The honing machine 10 also comprises an actuator unit 32 positioned onthe machine base 14 that can move the workpiece 12 back and forth alongthe horizontal spindle axis 30 via a track system. During operation theworkpiece 12 is moved radially away from the rotary table 18 so thatthere is no more direct contact between the workpiece 12 and the rotarytable 18, and the rotary table is essentially vibrationally disconnectedfrom the workpiece. Such a disconnection of the workpiece 12 preventsthe transfer of the vibrations and oscillations from the horizontalhoning operations via the workpiece 12 to the rotary table 18 and thusto other workpieces 12 or workstations.

Before a horizontal honing operation is carried out on the workpiece 12,the workpiece 12 is aligned in the actuator unit 32 such that ahorizontally aligned bore that is to be honed is arranged along thehorizontal spindle axis 30. In this example embodiment, the horizontalhoning unit 26 is firmly positioned on the machine basis 14 so that thehoning spindle 28 is immovable along the horizontal spindle axis 30. Thehoning spindle 28 or honing tool only carries out a rotation during thehorizontal honing operation. The workpiece 12 is moved back and forthalong the horizontal spindle axis 30 via the actuator unit 32, while thehoning spindle 28 or honing tool rotates so that the honing operationcan be carried out on the bore previously aligned along the horizontalspindle axis 30. After completion of the horizontal honing operation,the workpiece 12 is returned to the workpiece intake 22 of the rotarytable 18 and transported to the next workstation via rotation of therotary table 18 around its vertical rotary table axis 20.

The individual workstations can be a loading and unloading station, avertical honing station, a measuring station, or another horizontalhoning station 24. For example, the workstation indicated on the left inFIG. 1 by the workpiece 12 can be a loading and unloading station, andthe workstations indicated at the top and bottom of FIG. 1 viaworkpieces 12 can be vertical honing stations with vertical honing units(not pictured). In particular, the workstation indicated at the top ofFIG. 1 by the workpiece 12 can be used for vertical pre-honing, and theworkstation indicated at the bottom of FIG. 1 by the workpiece 12 can beused for vertical final honing. At least one of the workstations canalso be a measuring station, with which the honing operations carriedout at the respective bores can be evaluated and monitored. But it isalso possible for the measurement to be conducted with a measuring unit34 at a workstation that is not a measuring station.

The measuring unit 34 shown in FIG. 1 is arranged on the machine base 14via sliders such that post-measuring of the horizontal bore is possible,while, for example, the workpiece 12 is located in the workstation forvertical shape honing (see above).

FIG. 2 shows a side view of the honing machine 10 described by theinvention as shown in FIG. 1. It is clear that, in order to carry outthe honing in the horizontal honing station 26, the workpiece 12 isradially moved outward away from the rotary table 18 in order to achievethe aforementioned disconnection of the workpiece 12 from the rotarytable 18. Furthermore, the rotary table 18 in this example embodiment isan elevating rotary table. This means that the rotary table 18 can belowered after transporting the workpieces 12 into the next respectiveworkstation. The workpieces 12 then remain in the respectiveworkstations and are no longer connected with the rotary table 18. Therotary table 18 is thus not a medium by which unwanted vibrations oroscillations generated in the individual workstations can be transferredbetween the individual workpieces 12 or workstations.

FIG. 3 shows a top view of another example embodiment of a honingmachine 10 described by the invention. Here, too, are four workstationsshown, indicated by four workpieces 12, similar to the previous exampleembodiment. In the example embodiment shown here, the horizontal honingunit 26 is positioned on the machine base 14 such that the horizontalspindle axis 30 does not run through the rotary table axis 20.Accordingly, the workpiece 12 must be aligned along this horizontalspindle axis 30 with its horizontally aligned bore. This is done with arotational device not further explained herein.

In this example embodiment, the horizontal honing unit 26 is moveablevia tracks so that the horizontal honing unit 26, and thus the honingspindle 28, can move back and forth along the horizontal spindle axis 30with a honing tool. In order to carry out the horizontal honingoperations, the honing spindle 28 is lowered into the workpiece 12 orthe bore of the workpiece 12 to be honed by moving the horizontal honingunit 26 following alignment of the workpiece 12.

After completion of the horizontal honing operation, the workpiece 12 isonce again rotated by the rotational device (not pictured) so that thehoning operation can be evaluated and monitored by the measuring device34. The rotated workpiece 12 and its alignment are shown in FIG. 3 witha thin, dashed line. The measuring device 34 is also moveably positionedalong an axis on the machine base 14 via tracks. The horizontal honingand post-measuring can thus be carried out at the same workstation. Aseparate workstation for the post-measuring or post-monitoring of thehorizontal honing operations is not necessary. Nevertheless, a measuringstation may be provided as a workstation where only post-measuring iscarried out.

Similar to the previous example embodiment, the individual workstationscan be a loading and unloading station, a vertical honing station, a(additional) measuring station, or another horizontal honing station 24.

FIG. 4 shows a side view of the honing machine 10 described by theinvention as shown in FIG. 3. In this example embodiment, too, therotary table 18 is designed as an elevating rotary table in order toprevent the transfer/spread of unwanted oscillations or vibrations viathe rotary table 18.

1. Honing machine for carrying out honing operations on orthogonallyaligned bores in a workpiece, comprising: a machine base; at least onemachine-internal transport system arranged on the machine basecomprising a rotary table that rotates around a vertical rotary tableaxis and comprises multiple workpiece intakes which are arranged offsetfrom one another in the circumferential direction at a radial distancefrom the rotary table axis such that a workpiece inserted into aworkpiece intake can be successively moved along a circular path andpassed through various workstations of the honing machine via rotationof the rotary table; wherein at least one of the workstations is avertical honing station comprising at least one vertical honing unit,which has a honing spindle designed for honing of a bore aligned along avertical direction via a relative motion rotating around a spindle axisand translatory along the spindle axis, between the workpiece and thehoning spindle, wherein the spindle axis is aligned parallel to therotary table axis; wherein further one of the workstations is ahorizontal honing station comprising at least one horizontal honingunit, which has a honing spindle designed for honing of a bore alignedalong a horizontal direction via a relative motion rotating around ahorizontal spindle axis and translatory along the horizontal spindleaxis, between the workpiece and this honing spindle, characterized inthat the honing machine comprises an actuator unit that is arranged anddesigned to carry out the honing in the horizontal honing station bymoving the workpiece, wherein in particular the honing spindle of thehorizontal honing unit is arranged immovably in the honing machine forcarrying out the honing, or that the machine-internal transport systemis designed such that, to carry out the honing in the horizontal honingstation, the workpiece is moved away from the rotary table, and thehoning is carried out outside of the rotary table, in particular whereinthe workpiece is moved outside of the circular path where the rotarytable moves the workpieces.
 2. Honing machine according to claim 1,characterized in that the horizontal spindle axis extends along aprocessing direction and the translatory relative motion occurs alongthis axis during the honing, wherein this processing direction isparallel to a direction extending radially through the rotary tableaxis, yet is spaced from the rotary table axis.
 3. Honing machineaccording to claim 1, characterized in that there is a rotational devicein the horizontal honing station, so that the alignment of the workpiececan be changed such that the processing in the horizontal honing stationcan be carried out with a different alignment of the workpiece than inthe vertical honing station.
 4. Honing machine according to claim 1,characterized in that all workstations of the honing machine arearranged on the machine base.
 5. Honing machine according to claim 1,characterized in that the honing machine comprises at least two verticalhoning stations, wherein at least one vertical honing station comprisesa vertical honing unit moveably arranged on a portal-like carrier viasliders, wherein the honing units of all vertical honing stations aremoveably arranged on the carrier via sliders.
 6. Honing machineaccording to claim 1, characterized in that the honing machine comprisesa first workstation designed as a loading and unloading station, asecond workstation, wherein this is a first vertical honing station forpre-honing, a third workstation, wherein it is the horizontal honingstation, and a fourth workstation, wherein this is a second verticalhoning station for the final honing or other processing, wherein thetransport direction of the rotary table is from the first to the fourthworkstation and back to the first workstation.
 7. (canceled)
 8. Methodfor carrying out honing operations on orthogonally aligned bores in aworkpiece, wherein the method comprises the following steps: receipt ofthe workpiece at a rotary table that rotates around a vertical rotarytable axis; transportation of the workpiece successively between variousworkstations along a circular path via rotation of the rotary table;wherein at least one of the workstations is a vertical honing station inwhich a bore aligned along a vertical direction is honed via a relativemotion rotating around a spindle axis and translatory along the spindleaxis, between the workpiece and honing spindle, wherein the spindle axisis aligned parallel to the rotary table axis; wherein further one of theworkstations is a horizontal honing station in which a bore alignedalong a horizontal direction is honed via a relative motion rotatingaround a horizontal spindle axis and along the horizontal spindle axis,between the workpiece and honing spindle, characterized in that in orderto carry out the honing in the horizontal honing station, the workpieceis moved, and the honing spindle of the horizontal honing unit is heldimmobile at least in the direction of the translatory relative motion,or that in order to carry out the horizontal honing, the workpiece ismoved away from the rotary table and the honing is carried out outsideof the rotary table, wherein the workpiece is moved outside of thecircular path where the rotary table moves the workpieces.
 9. Methodaccording to claim 8, characterized in that the horizontal spindle axisruns along a processing direction and the translatory relative motionduring the honing occurs along this axis, wherein this processingdirection is parallel to a direction extending radially through therotary table axis, yet is spaced from the rotary table axis.
 10. Methodaccording to claim 8, characterized in that the alignment of theworkpiece is changed before the horizontal honing.
 11. (canceled) 12.Method according to claim 8, characterized in that a honing machineaccording to claim 1 is used to carry out the method.